1. Field of the Invention
This invention is directed to a hand-held power-operated shears. Although designed for and intended primarily for dismemberment of poultry into parts for processing, the shears may obviously be used for other cutting operations requiring repeated and fatiguing operation of a shears.
2. The Prior Art
The following U. S. patents are exemplary of the prior art:
Wild; 2,733,506; Feb. 7, 1956 PA1 Bidin; 2,791,028; May 7, 1957 PA1 Dawson; 2,818,643; Jan. 7, 1958 PA1 Kellersman et al; 3,165,780; Jan. 19, 1965 PA1 Fischer et al; 3,177,583; Apr. 13, 1965 PA1 Frenzel; 3,255,525; June 14, 1966 PA1 Jahnke; 3,893,237; July 8, 1975 PA1 Pellenc; 4,109,381; Aug. 29, 1978 PA1 Ailey; 4,791,726; Dec. 20, 1988
Essentially the cutters of these patents each has a pair of blades, at least one of which is connected to a piston and piston rod in a fluid operated cylinder, which is actuated by a trigger. In most instances the return stroke is the result of spring action, but the Wild, Ailey and Pellenc patents show a positive fluid-powered return. Both blades are movable in the cutters of the Jahnke and Bidin patents. In several of the patents, as exemplified by Frenzel, Bidin, Jahnke and Pellenc, there is an extra link between the movable blade and the piston rod. Others have a direct linkage. The Kellersman et al, Jahnke and Ailey patents refer to the use of power shears specifically for cutting poultry.